Mattis skittish on Syria

7/20/13 8:06 PM EDT

ASPEN, Colo.—Recently retired CENTCOM commander James Mattis warned Saturday that a limited U.S. intervention in Syria will be costly and ineffective, while he also suggested that the U.S. public is not invested enough in resolving the fight there to support broader U.S. involvement.

"We all want to do something to stop this but...we have no moral obligation to do the impossible and hawk our children's future just because we have the desire to do something," Mattis said at the Aspen Security Forum. "When you go to war, it cant be a half step."

"If Americans take ownership of this, this is going to be a full-throated, very, very serious war. Anyone who says this is going to be easy or a no-fly zone is going to be cheap, I would discount that at the outset," the retired four-star Marine general said.

Mattis said the U.S. also needs to define what "end state" it is seeking in Syria, if further action is to be taken. "Otherwise, you invade a country and pull down a statue and then say: 'Now, what do we do?'….Know what I mean?" he said, in an obvious reference to the chaotic aftermath of the U.S. toppling of Saddam Hussein in Iraq.

Mattis questioned the value of a no-fly zone, since the vast majority of the violence involves ground forces and police. "I guarantee you if ordered to do it, CENTCOM can do a no-fly zone....It will be very expensive....It will drain the treasury," he said. "And the killing will go on on the ground....Syria fighting a total war can defeat us fighting a limited war."

In a public interview with CNN anchor Wolf Blitzer, the former CENTCOM commander left open the possibility of military aid to the Syrian opposition, but said that kind of effort needs to be fast and major enough to be decisive. He also said U.S. special forces or Central Intelligence Agency personnel need to accompany those who have been trained and armed by the U.S. "to keep an eye on what they're using the weapons and training for."

Despite all his warnings and reservations, Mattis said allowing the conflict to drag on could be disastrous. "This war needs to be ended as rapidly as possible. That's the bottom line," he said.